1. Technical Field
This invention relates to an improvement in a hose connection vacuum breaker and backflow preventer which is attachable to the hose connection of a faucet or the like and, more particularly, to such a device which is self-draining to provide automatic draining of a faucet, hydrant, or sillcock to which the device is attached when a separate or integral connection for a hose or other liquid conductor is detached from the device.
A hose connection vacuum breaker and backflow preventer is operable to permit normal fluid flow to a hose or the like when a faucet is open and to prevent reverse flow back to the supply. In addition to preventing backflow, atmospheric vents are effective to break any vacuum.
2. Background Art
The assignee of this application markets devices of the hose bibb type. A device can be permanently attachable to the hose connection of a fluid source, such as a faucet, hydrant or sillcock and a hose connector may be connected to it. One such device has a tubular body with atmospheric vent holes and a flexible annular diaphragm normally urged to a position to prevent backflow and to be in nonobstructing relation with the atmospheric vent holes. When there is fluid flow from the source, the diaphragm is deflected from its seated position to close the atmospheric vent holes and permit flow through the device. When the supply is cut off, as by closing the faucet, the diaphragm is spring-urged by suitable means to its closed, seated position to prevent backflow and move out of obstructing relation with the atmospheric vent holes.
A backflow preventer and vacuum breaker of the hose bibb type is shown in Butcher et al. U.S. Pat. No. 3,670,760, owned by the assignee of this application.
Another type of device has drain openings and an external ring for closing the drain openings and which can be moved to a position to permit flow through the drain openings.
The prior devices have had to be manually actuated to achieve draining when the hose connector is detached. Failure to drain the faucet, hydrant or sillcock, especially freeze-proof sill cocks could result in freezing of the trapped water and consequent piping and/or valve rupture or retention of stagnant water. Considerable property damage may result in the case of freezing of the trapped water and resulting pipe rupture. If stagnant water is trapped, resulting bacterial growth may cause contamination.
The device shown in the Butcher et al. patent has a manually engageable member associated with the diaphragm to flex the diaphragm away from its closed, seated position whereby water may drain through the device.
The automatic draining of a faucet, hydrant or sillcock when an integral or separate connector for a hose or the like is removed from the hose connection vacuum breaker and backflow preventer is a distinct improvement over the prior art.